X-ray tube focusing apparatus



. livfiach 7 119% E. R. GOLDFIELD ET AL 2,499,950

X-RAY TUBE FOCUSING APPARATUS 5 Sheets-Sheet l Filed June 15, 1946mum/ram DW/IV R GoLDF/ELD fiaamr J JrAvA 87 &

Mwfih 9 1950 ER. GOLDFIELD EI Al... 2,499,959

X-RAY TUBE FOCUSING APPARATUS Filed June 13, 1945 5 Sheets-Sheet 2 A7708 NE YJ March 11950 1 E. R. GOLDFIELD ET AL. 23 9 X-RAY TUBE FOCUSINGAPPARATUS Filed June 13, 1946 I 5 Sheets-Sheet 3 I INVENT AJ [ow/N R.GOLDF/'LO fiOdif/YT J JrAvA 5 [DGAR I BAJT/N JR.

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ATTORNEY-5 March 7, 1950 E. R. GOLDFIELD ET AL. 2,499,950

X-RAY TUBE FOCUSING APPARATUS Filed June 13, 1946 5 Sheets-Sheet 4#vvawrom t fow/A/ R. GOLDF/ELD ROBERT J JTA VA foe/1R J EAJT/N'JR.

ATTORNEYJ March 7, 1950 E. R. GOLDFIELD ET AL 2,499,950

X-RAY TUBE FOCUSING APPARATUS Filed June 13, 1946 5 Sheets-Sheet 5 few/NE. GOLOF/L'LD 80mm? J." JrAvA EDGAR J EAJTIN in.

Patented Mar. 7, 1950 2,499,950 X-RAY TUBE FOCUSING APPARATUS Edwin R.Goldfield and Robert J. Stava, University Heights, and Edgar J. Bastin,Jr., Cleveland, Ohio, assignors to Picker X-Ray Corporation ViaiteManufacturing Division, Inc., Cleveland, Ohio, a corporation of OhioApplication June 13, 1946, Serial No. 676,410

3 Claims.

The invention relates to novel and improved means for supporting anX-ray tube. It particularly relates to novel and improved means wherebysuch tube may be readily and conveniently adjusted in height, ininclination to the horizontal, and in swinging movement in a horizontalplane, so as to facilitate directing the tube on certain desired areasof a subject when said subject is disposed in certain positions relativeto the tube.

The apparatus herein to be described is especially adapted for routineexamination of specific anatomical regions of a continuous succession ofpatients. It sometimes becomes desirable to examine all employees of anindustrial plant or the like. In a routine examination or periodicalcheck of this nature, it is of course desirable that the project beconducted as rapidly and efliciently as possible, consistent withreliable results. It must normally be expected that the technicianoperating the X-ray apparatus will be confronted by a considerablevariation in the physical characteristics of successive subjects, andconsequent adjustment of the apparatus for such variations mustnecessarily be made, and should be made both readily and rapidly.

In one preferred adaptation of the apparatus herein to be described, andas set forth in our copending application Serial No. 624,172, filedOctober 24, 1945, the subject stands between the X-ray tube and afluorescent screen, both screen and tube being maintained in suchposition that the radiation generated by the tube is directed towardsthe screen producing thereon a visible image of familiar shadowgraphtype. Such image can be studied visually onthe screen, or can bephotographed for permanent record, and later studied.

In a routine examination of a substantial number of subjects, eachsubject steps in succession to a predetermined position, for example ona pedestal or platform which may be raised or lowered to bring anydesired portion of the subjccts body in alignment with and between thetube and screen, and the examination is thereupon made or the picture istaken. Those skilled in the medical arts are familiar with the fact thatthe compensatory adjustment for subject height mentioned above does notnecessarily givecomparable results with all subjects, and that anadditional adjustment, within a limited range, is often desirable. Thisis particularly the case when special effects are desired, for examplein the achievement or avoidance of special shadow effects inexaminations in the general area of the 2 heart and the lungs. Sometimesthe clavicle structure requires an X-ray beam directed slightly upwardlyor slightly downwardly for the best results. This is easily accomplishedby means of our novel tube support.

It is accordingly desirable that the tube support be provided with meansfor effecting minor but significant changes in the height of the tube,and also in the angularity of the projected radiation with respect tothe center of the screen. It is further desirable that the tube supportbe rotatable in a horizontal plane so that examinations may be made ofanimate or even inanimate subjects which may not occupy the standingposition hereinabove described.

An object of the present invention is to provide novel and improvedmeans for adjusting the vertical height of an X-ray tube, and forsimultaneously varying its projection axis with respect to thehorizontal, so that axis still intersects the center of the fluorescentscreen.

A further object is to provide novel and im-- proved means forfacilitating horizontal move-- ment of the tube carrying means towardsand from the screen, and for locking the mechanism in desired position.

A further objectis to provide novel and improved means forpermittingswinging movement of the tube assembly in a horizontal plane, and forlocking the assembly when the desired position is attained. Otherobjects and advantages will be apparent from a study of the followingdescription of one embodiment of the invention, in conjunction with theaccompanying drawings of said embodiment, in which:

Fig. 1 is a sideelevational view of an X-ray tube support and associatedstructure for imparting the desired positional adjustments ashereinabove indicated;

Fig. 2 is a fragmentary front elevational View, somewhat enlarged, asseen from the right of Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on the'line 4-4 of Fig. 1;

Fig. 5 is a sectional view taken on the same line as Fig. 4, but showingcertain of the parts in an operating position differing from that ofFig. 4;

Fig. 6 is a sectional view taken on the line 6-45 of Fig. 3;

Fig. 7 is a sectional view taken on the line 1-? of Fig. 1;

Figs. 8 and 9 are sectional views taken respectively on the lines 88 and9-43 of Fig. '7;

Figs. 10 and 11 are detail views in vertical section, correspondinggenerally to the showing of the same parts in Fig. 1, but illustratingrespectively different operating positions;

Fig. 12 is a fragmentary perspective view, normally contacting partsbeing exploded for greater clarity, the view illustrating details ofcertain associated elements in the tube supporting structure;

Fig. 13 is a view in side elevation, and somewhat reduced, illustratingthe relationship of the several possible tube positions to thefluorescent screen.

Speaking first generally, an X-ray tube 20, shown in outline in Fig. 1,is fixed in position on the rear face of a mounting plate 2|. Inalignment with the zone of emergence 22 of the rays from the tube, theplate is provided, on its front surface, with a hollow cone 23, or otherdevice having walls diverging away from said zone of emergence. The axisof projection of the X-rays is indicated in Fig. 1 by the arrow B, andthe cone is constructed from material relatively impervious to X-rays sothat it restricts the bundle of emergent rays to such cross sectionalarea as is desirable or necessary for its intended purpose. Thefluorescent screen heretofore mentioned, and shown only diagrammaticallyin edge view in Fig. 13, is spaced from the cone a distance sufficientto permit a subject to stand between the cone and the screen. Actually,as will later appear, the distance is carefully determined so as to beconformable to factors incident on tube height and the angularity of theprojection axis in the several possible operating positions.

The mounting plate 2| is supported on a tube stand 24, movable endwiseon the carriage, namely, to the right and left in Fig. 1. Mechanismwhereby endwise movement is accomplished and locking means for fixing apredetermined position, will later be described.

The carriage 25 is rotatable in a horizontal plane around a fixed axison the top of a suitable support such as the column 26. Positioned andlocking means are provided, and will later be described, fordetermining. and fixing the required angle of the carriage in saidhorizontal 1 plane.

The upper portion of the stand 24 and the lower portion of the mountingplate 2| are provided with complementary interengageable positioningmeans which simultaneously serves two purposes. namely to adjust theheight of the tube and plate, and to vary the angle of the axis ofprojection of the X-rays to compensate for the height change. Means forfixing a predetermined height and angularity of the projected beam islikewise provided.

The means for accomplishing all said movements, and the respectivelocking means for the same, will now be described.

Considering first the rotary movement of the carriage on the top ofcolumn 26, and referring particularly to Figs. 1, 2, 3 and 7, the top ofthe column is outwardly flanged at 30 to provide a seat for an indexingplate 3| on top of which is fixed a circular pilot plate 32 forming theaxis around which the carriage turns. The carriage 25 is of trough-likecharacter having a horizontal bottom wall 33, two vertical side walls34, and two outturned shoulders 35 at the top of the side walls. Thebottom wall is provided with a centrally located aperture 36 (Fig. 3)which is disposed to have a rotating friction fit around the pilot plate32. After disposition of the carriage on the indexing plate 3 I, andaround the pilot 32, a retaining plate 3! is placed above the assembly,with its edges overlapping the edges of aperture 36. The indexing plate3| and the flange 30 of the column 26 are maintained in fixed positionwith respect to each other by screws 38. The retaining plate 31, thepilot plate 32 and the indexing plate 3| are maintained in fixedposition with respect to each other by screws 39. The assembly, as bestseen in Fig. 3, is thereby so arranged that, if desired, the retainingplate and pilot are separately removable merely by removing screw 39,the indexing plate being still retained by the screws 38 as aforesaid.

The means for permitting rotary movement of the carriage having beenthus described in the last preceding paragraph, the locking andpositioning means therefor will now be explained.

The indexing plate 3| (Fig. 7) is generally circular in peripheralcontour, and is provided with edge slots 43, 43a, 43b, circumferentiallyspaced approximately forty-five degrees apart. The lock lever 44,swingable on a pivot pin 45 on the under side of the carriage, has anupwardly extending pin 46 which passes through a slot 41 in the bottomwall 33 of the carriage, and the upper end of said pin is normallyseatable in one of the spaced slots on the index plate, therebypreventing rotation of the carriage. Disengagement of pin 46 from anyslot is effected by clockwise movement of the lever 44 (Fig. 7) suchmovement being achieved by means of a release handle 48 underlying andcarried by the carriage 25 as best seen in Fig. 8. One end of therelease handle is pivotally connected at 49 to lock lever 44, and theother end of the release handle, near the extremity of the carriage, ishooked to provide a finger pull 5!]. The release handle is reciprocablymounted beneath the carriage b a screw 5| which has a portion 52 passingthrough a slot 53 in the lever. The assembly consisting of the lockinglever and release handle is biased to looking position by spring 54which is fixed at its opposed ends to handle 48 at 55, and to the bottomwall of the carriage at 56.

It will be apparent that when the release handle is drawn to the right(Figs. '7 and 8) pin 46 is unseated from slot 43 and the carriage may berotated approximately ninety degrees counter clockwise until pin 46reaches slot 4317. Once the pin is out of slot 43, and rotationcommences, the handle 48 may be released, whereupon spring 54 maintainsthe pin in sliding contact with the periphery of the indexing plate 3|.The pin will naturally drop by spring bias into the next slot whichpasses beneath it.

The mechanism permitting endwise movement of the tube stand 24 on thecarriage 25 will now be described, referring particularly to Figs. 1 to6 inclusive, and to the detailed perspective view shown in Fig. 12. Allparts shown in Fig. 12 are normally in interfitting engagement, but theview is exploded for clarity in illustrating the specific contour of thevarious elements.

The tube stand 24 has an upstanding front wall anda pair of spaceddownwardly and rearwardly inclined side walls 6|. Between said sidewalls, and across the lower edge of the front wall is a transverse floorstrip 62. Along their lower edges the side walls 6| are upwardly cutaway to provide spaced arches 63. The wall portions between the archesare inturned to provide spaced inwardly inclined feet in the plane ofthe floor strip.

A base plate 61 rests upon carriage 25, straddling the trough portion,and being supported on the carriage shoulders 35. The base plate has adepressed longitudinally centrall located floor 68, and side edge ridingflanges 69. Along the outer edges of the flanges 69 are a plurality ofspaced downturned guiding fingers Ill. Underneath the two flanges 69 area pair of respective bearing strips II which are readily slidableendwise on the carriage flanges 35.

A lock plate 13 rests transversely on the riding flanges of base plate61 and has spaced downwardly extending fingers 14 which pass within therecesses '15 in the base plate. The finger tips 76 are inturned beneathflanges 35 but with freely moving vertical clearance as shown in Fig. 5when the plate is in unlocked position. The tube stand 24 overliesplates 61 and 13, the feet 65 of the tube stand being rigidly connectedwith plate 61 and bearing strips H as by bolts 11 passing through holesI99 and |9| (Fig. 12). In the assembled position, and unless looked aslater described, the lock plate 13 is freely floating, to a limitedextent, as permitted by the clearance above finger tips 16 as aforesaid.The fingers 14 of the lock plate have edge clearance between their sideedges and the edges of feet 65, and have vertical clearance by reason ofthe height of arches 63. In said assembled position the lock plate isloosely retained between the tube stand and the base plate. The floorportion of the base plate 61 is provided with a pair of opposed,upturned lugs 19, one at each end, the lugs having a pair of alignedapertures 89 to serve as end bearings for a shaft 8| upon which arefixedly carried two locking cams 82. The looking plate 13 is providedwith downturned end covers 83 which lie outside lugs 80 and which havearches 84 aligned with the bearing apertures 80.

A glance at Figs. 4 and 5 for example will indicate that when shaft BIis rotated from the position shown in Fig. 5 to the position shown inFig. 4, the raised portion of cam 82 contacts the lowe face of lockplate 13 and brings fingers 16 into tight contact with the lowersurfaces of shoulders 35 of the main carriage. This prevents endwisemovement of base plate 61 for the reason that the base plate rests onthe upper surfaces of the carriage shoulders and operation of the camsproduces an opposed gripping force on the lower surfaces of the sameshoulders. As best seen in Figs. 1, 2 and 3 the end of the shaft 8|extends under and in front of the wall 60 of stand 24, and a crank arm85 is fixed to said shaft end for rotation of the shaft. Stop pins 85 inwall 60 provide limit rests for arm 85.

When it is desired to move the tube and stand assembly endwise on thecarriage, the crank arm 85 is swung from the locked cam position (Figs.2 and 4) to the unlocked cam position (Fig. 5), after which endwisesliding movement can be produced between bearing strip H and carriageplate shoulders 35. The tube stand of course moves with the bearingstrip.

To prevent accidental removal of the tube and stand assemlby a stop 2 issecured to bottom plate 33 of carriage 25 (Fig. 12) and a slot I03 iscut in plate 61 to receive lever I04, pivotally mounted by means (notshown) so that a portion of lever HM engages stop I92 in the position ofthe parts shown in Fig. 12. Lifting the lever I94 causes it to clearstop |02 so that plate 51 may be removed from carriage 25.

Still another adjustment of the X-ray tube assembly is one whichcombines upward or downward movement with relation to the carriage andsimultaneous tilting movement of the tube to vary the angle of theradiation beam with respect to a horizontal plane. The mechanism to bedescribed automatically secures the proper tilting angle when the heightis changed, with the result that the central or axial beam in the bundleof projected rays always intersects the center of the fluorescent imagescreen. In connection with the following description reference may behad to Figs. 1, 2, 10, 11 and 13.

The upper portions of the angular side walls 6| of the tube stand areprovided with matched pairs of horizontally aligned socket slots in avertically ascending series, three such pairs 81a, 81b, and 8'7 c beinghere shown. The tube mounting plate 2| has amxed thereto a crossbar 8Bthe ends of which extend laterally beyond the mounting plate and areseatable in one or other of the aforesaid aligned pairs of sockets.Since such sockets open upwardly and rearwardly, the mounting plate maybe handled manually, and the crossbar ends rested in any desired pair ofsockets.

Tilting movement of the mounting plate is automatically controlled bymeans of the following mechanism.

The front surface of the mounting plate 2| is provided with threevertically spaced bosses 89, 99 and 9| respectively, each one perforatedand threaded to receive a suitably threaded shank of a thumb screw 92.Said shank extends through a bushing Q3 lining an aperture in the frontwall 69 of stand 24. Bosses 89 and 9| are of equal height from thesurface of plate 2|, and the middle boss 90 is somewhat shorter. Bycomparing Figs. 1, l0 and 11 it will be apparent that when the mountingplate is in the intermediate position of Fig. 1, boss 99 is engaged bythe thumb screw shank, and the thumb screw is then turned until bosses89 and 9| make contact with the rear surface of wall 69, thereby placingthe mounting plate 2| and the front wall 69 in parallel relationship. Insuch position the central axial beam of the X-ray radiation exactlyintersects the screen center. This is the full line position R of Fig.13. v

If the mounting plate is placed in the top position (Fig. 10) boss 9| isabove the top edge of wall 60 and bosses 89 and 90, being of unequalheights, the plate 2| is tilted as shown so as to incline radiation axisR downwardly. This is the dot-dash position Ri'of Fig. 13.

The upward tilt of the radiation axis in the lowest plate position, asshown in Fig. 11 and in dotted line R2 in Fig. 13, is achieved byproviding an aperture in wallBU which permits boss 89 to extendoutwardly therethrough while boss- 9| is engaged by the thumb screwshank. As best seen in Fig. 11 this; permits a backward tilt of theplate 2| giving the radiation axis an upward inclination such as isnecessary to intersect the screen center as aforesaid.

The vertical height between sockets 81a, 81b, and 810, the angle oftilt, and the distance to the screen are such that the radiation axesfrom three positions intersect at the center C of the screen 96 as shownin Fig. 18.

When making a routine check, for example of heart or lung conditions ofa succession of patients, the tube stand and fluorescent screen aremaintained at a fixed distance from each other. This distance isdetermined by the point 7'. at which the various radiation axesintersect, such point in turn depending on the vertical displacement ofthe tube mounting plate in the severahoperating positions, and theangular tilt of said plate in each said position. As hereinbeforeindicated, the point of intersection should coincide with the center ofthe fluorescent screen.

The side of the carriage may have afi'ixed thereto ascale98 (Fig. 1)graduated in inches or other units,- and the'endwise movable portion ofthe apparatus, for example the base plate 63, may carry a pointer 99,which travels along the scale when the tube stand is moved. Normally thedistance between the carriage support and the fluorescent screen isfixed, so that the scale reading ma directly indicate the distance fromthe tube target to the screen. Such endwise movement isusuallynecessary'only when a tube is replaced by another of diiferentstructural characteristics, and in'which the tube target is not inidentical position with respect to the mounting plate.

In the normal set up, as hereinabove mentioned, wherein the tube, thescreen, and the patient are insubstantially fixed and predeterminedrelative position, swinging movement of the carriage around its pilotpivot is entirely unnecessary, and the pin 460i the lock lever 44maintains an established position in a specific slot in the indexingplate 3 l. Swinging movement of the carriageis available, for example ifit becomes desirable or necessary to direct the radiation angular-1yaway from the conventional alignment as above noted. The slots '43, 43a,43b, in the indexing plate may be spaced any suitable angular distanceapart to provide a choice of stopping points, although as shown herein,and'particularly' in Fig. 7, the normal swing does not exceed ninetydegrees, being limited by the stop shoulders 94on slots 43 and 432).

Major adjustments in the vertical position of the carriage or the screenmay be made in any conventional manner, by rack and pinion, worm andgear, or otherwise. Novel means for doing thisareshown in the abovementioned copending application. The novel and improved means here shownand described for effecting minor but necessary adjustments in bothheight and inclination angleirepresent' significant contributions to thesuccessful operation of the apparatus.

When the apparatus is in use, the observer, or the camera" forphotographicall recording the image produced on the fluorescent screen,occupies a position tothe left of the screen 96 as sh'own'in Fig. 13.

What we claim is:

1; In "X-ray-apparatus' wherein an X-ray tube housing is maintainable insubstantially fixed horizontal relationship to fluorescent screen, meansfor supp'orting'said tube housing including pins horizontally aligned onopposite sides of saidhousing on an axis at right angles to the X -raybeam, a bracket having a plurality of pairsof upwardly opening slots atdifferent vertical levels adapted to receive said pins, and stopsengaging between said bracketand said housing in ea'ch'position' to tiltsaid housing to cause the 8; X-ray beam to strike said screen atapproximately the same point.

2. In X-ray apparatus wherein'an X-ray tube housing is maintainable in'substantially. fixed horizontal relationship to a fluorescent screen,means for supporting said tube housing including a bracket and includingcoacting sets of pin members and slot members, one of said setsconnected with said housing and the other set connected with saidbracket, said supporting means including a plurality of one of said setsof members at difierent vertical heights, each of said sets of pin andslot members providing a horizontally extending pivotal axis for saidhousing, said housing being tiltable about said pin and slot members tovary the inclination of the X-ray beam, and stop means between saidbracket and said housing when supported on each of said sets of pin andslot members to tilt the housing to cause the X-ray beam to strikesubstantially the same portion of said screen.

3. In X-ray apparatus wherein an X-ray tube housing is maintainable insubstantially fixed horizontal relationship to a fluorescent screen,means for supporting said tube housing including a generally verticalmounting plate having pins horizontally aligned on opposite sides ofsaid housing on an axis at right angles to the X-ray beam, a brackethaving three pairs of upwardly opening slots at different verticallevels adapted to receive said pins, three bosses on said plate spacedvertically and positioned to engage against said bracket when said pinsare in said slots, a screw held in said bracket and adapted whenthreaded into said plate to pull said bosses toward said bracket, eachof said bosses threaded to receive said screw, the middle of said bossesbeing of lower height than the top and bottom bosses, which are of equalheight, whereby when said screw is threaded into said middle boss saidplate is substantially vertical, said top boss being above said bracketwhen said screw is threaded into said bottom boss, whereby when saidscrew is threaded into said bottom boss said plate is tilted with itsupper end forward, and there being an opening in said plate to receivesaid bottom boss when said screw is threaded'into said top boss,whereby, in the last named'position, said plate is tilted with its upperend rearward.

EDWIN R. GOLDFIELD. ROBERT J STAVA. EDGAR J. BASTIN, J a.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,797,303 Wappler etal Mar. 24,1931 1,871,005 Mutscheller et al. Aug. 9, 1932 2,156,170 Augustin et a1Apr. 25, 1939 2,167,114 Kieffer July 25, 1939 2,235,144 Colcher Mar. 18,1941 2,400,455 Donaldson May 14, 1946

